Running takes a lot out of you. Sometimes when people start running for the first time or after a long period of inactivity, they go into their closet, find a pair of runners and go. And, they might be okay, but quite often, it is time for a new pair of shoes. Think about it... your running shoes are what's between your body and the hard surfaces you run on. They absorb the force of your feet hitting the ground multiple times in a minute. They help take the pressure off your knees and ankles. Did you suddenly start hurting? Have you got shin splints? Knee aches? There is a good possibility that something as simple as new shoes could help you out.
And, don't buy just any shoes. Go to an actual running store and have one of the staff that's trained, fit your feet and make sure you get into the shoes you need. There are many types of shoes. Some provide stability, others provide cushioning, some are designed to be super lightweight and only good for racing. It's important to have shoes that match your feet and how you run. If you pronate, then having a neutral shoe is not going to help you.
Once you know what kind of shoes you need, then go for comfort. Shoes come in all sorts of colours and shapes, but you can't buy shoes based on that. You need to buy the ones that match what you need and feel comfortable on your feet. They might not be the snazziest pair, but if they get you safely through your training and race without incident, then they are the best pair.
And shoes don't last forever either, so even if you bought a brand new pair 3 years ago, and haven't used them much, maybe it's time for a new pair. That way, you know they are offering you the support you need. If you keep a running log, you'll know how far you've gone, and then you can replace them once you've logged 500 km or more.
Shoes are expensive, but they are nothing compared to being sidelined because of an injury, so if something started hurting that never used to, or you really can't remember when you got your shoes, or if they were shoes that have done you well in six other sports, take the time to go buy new ones. You will be glad you did!!